1. Field of the Invention
This invention pertains to a method of and apparatus for producing useful work. More particularly, this invention relates to a method and apparatus for obtaining improved conversion of caloric energy to mechanical energy for doing work.
2. Description of the Prior Art
The various methods of the prior art have been given various names for the respective cycles. Typical of these are Newcome, Watt, Sterling, Lenoir, Rankine, Brayton, Otto, Diesel and the like. These prior art methods suffer from the common short coming which is generally poor overall conversion of caloric energy to mechanical energy. The very best engines typically waste twice as much energy as they can convert into mechanical power. One large source of energy loss is high exhaust temperatures. Another loss results from untimely heat exchange between the working fluid and interior engine surfaces. Still another significant loss is the mechanical losses due to friction because of the high working pressures that have resulted from the general misconception that high efficiency requires high compression. Moreover, the structural demands of high temperature, high compression and high stresses have increased the costs of apparatus. Where internal combustion was a source of energy within an engine, there have been these disadvantages plus the disadvantage resulting from incomplete combustion within the engine and the resulting pollutants being discharged into the atmosphere.
Experience has indicated that it is desirable that the method and apparatus for producing useful work should provide one or more of the following features not heretofore provided.
(1) The method and apparatus should follow a work cycle in which the fluid that is exhausted is a relatively lower temperature than the fluid of the prior art work cycles.
(2) The method and apparatus should follow a work cycle which avoids unwanted heat exchange between the fluid and engine components so as to conserve energy and improve efficiency.
(3) The method and apparatus should follow a work cycle that enables low pressure operation and, hence, have low structural requirements; in contrast to the high pressure and high stress at high temperature.
(4) The method and apparatus should reduce pollutants.
(5) The method and apparatus should be widely useful with the different known sources of energy such as prime exothermic reactions of fission, fusion, reduction and be applicable to secondary sources such as process waste heat, refuse disposal and electromagnetic radiation.
(6) The apparatus for producing work should have a construction in which the moving parts, valves, dynamic seals and the like need not be subjected to the heat source high temperature, thereby increasing the peak temperature permissible in the engine and improving caloric energy conversion efficiency.
From the foregoing it can be seen that the prior art has not provided the totally satisfactory solution by providing method and apparatus that have the foregoing features.